Research on the Microstructure and Micro-mechanics Properties of NiAl Intermetallic Coatings

摘要

A new thermal spraying technique, electro-thermal explosion directional spraying (EEDS), was used to prepare NiAl intermetallic coatings. The microstructure, elements distribution and phase structures were determined by means of SEM, EDAX and X-Ray diffraction, respectively. Micro-mechanics properties were tested by using nano-indentation tester. The wear resistance of the coating was also investigated. Results showed that NiAl coating was characterized by compact construction. The main phase of the coating was Ni-Al and the content of oxide was little. The obvious elements diffusion showed that the bond between the coating and the substrate was metallurgical one. The nano-hardness and the modulus were 7.6 Gpa and 218.8 Gpa, respectively. The coatings processed good wear resistance and the main wear failure mechanism was the micro-plowing.